Heat exchange apparatus

ABSTRACT

In cooling a gas, such as air, the finned cooling coils are flooded with a recirculated organic antifreeze medium to prevent icing of the coils. At very low temperatures, say -40* F, this medium becomes very viscous and difficult to apply without insufficiencies in some areas and overflooding in other areas. Either condition, results in obstruction and reduction of air cooling efficiency of the finned coils. The present invention provides moving spray nozzles applying the viscous antifreeze medium in a pattern avoiding both of these conditions. Preferably the spray nozzles are oscillated and discharge flat fan-shaped, overlapping streams. Preferably they are turbine-driven by a small by-passed part of the pressurized medium supplied to the nozzles.

United States Patent 1191 Stutz 1451 Aug. 13,1974

1 1 HEAT EXCHANGE APPARATUS [75] Inventor: Robert C. Stutz, Kenmore, NY.

[73] Assignee: Niagara Blower Company, Buffalo,

22 Filed: Ma 24,1973

21 Appl. N6; 363,515

52 us. or 62/2'82, 62/82, 62/310, 165/85, 165/95, 165/104 51 1111.01. F2Sd 21/00 58 Field of Search 62/282, 82, 80, 310-, 134/181, 180; 165/85 56 References Cited UNITED STATES PATENTS 2,421,293 5/1947 Shawhan 62/82 X 2,502,763 4/1950 Swift 134/181 X 2,568,891 9/1951 Kals 62/282 x- 2,740,416 4 1956 Halsey 134/181 x 1 2,824,648 2/1958 Bear 134/181 x 3,169,381 Persson 62/282 X 3,210,010 10/1965 Dclapena 134/181X Primary Examiner-Albert W. Davis, Jr. 0 Assistant Examiner-S. J. Richter 57 ABSTRACT In cooling a gas, such as air, thefinned cooling coils are flooded with a recirculated organic antifreeze medium to prevent icing of the coils. At very low temper- 1 atures, say 40 F, this medium becomes very viscous and difficult to apply without insufficiencies in some areas and overfiooding in other areas. Either condition, results in obstruction and reduction of air cooling efficiency of the finned coils. The present invention provides moving spray nozzles applying the viscous antifreeze medium in a pattern avoiding both of these conditions. Preferably the spray nozzles are oscillated and discharge flat fan-shaped, overlapping streams. Preferably they are turbine-driven by a small bypassed part of the pressurized medium supplied to the nozzles.

9 Claims, 7 Drawing Figures PAIENIEU Am; 1 31974 sum 1 or 2 W, N f l PAIENIE AUG 1 31974 SHEEI 2 BF 2 looding insome areas is not particularly disadvantageous, and hence using an excess of spray nozzles to insure complete flooding is not too disadvantageous.

However with the high viscosity of the recirculated medium required for very low temperature work, the numberof spray nozzles would have to be increased to a point where the cost of the equipment would be excessive, but, more important, the overlapping services of the fixed nozzles would result in excessive blinding of the coils by an excess of the viscous antifreeze medium, and reduction in their efficiency.

SUMMARY OF THE INVENTION The improved and novel spray system of this invention provides a plurality of moving nozzles which discharge flat fan-shaped streams of viscous antifreeze medium. The streams meet or overlap slightly to cause the antifreeze medium to impinge upon the array of cooling coils and fin plates from end to end. The nozzles are fixed to a common spray conduit and oscillate about its axis. They swing to and fro across the cooling coil bank to thereby completely and uniformly wash the tins of the cooling coil bank with adequate but minimum amount of antifreeze medium. This unique system provides efficient de-icing with a minimum number of spray nozzles and a minimum volume of antifreeze medium.

The principal object of the present invention is to provide an improved gas or air cooler in, which the coils and tin plates are uniformly sprayed with'a viscous antifreeze medium to prevent icing of any part thereof.

cross section formed by side walls 12 and 14 and end walls 16 and 18. The cooling surface comprises vertically stacked, horizontal banks 20 and 22 of return bend tubular coils 24 having upper and lower legs 26 and 28; thelower legs 28 being connected to an inlet header 30 having inlet nipple 32 and the upper legs 26 being connected to an outlet header 34having an outlet nipple 36. Rectangular fin plates 38 are carried on the tubular cooling coils 24, tightly strung in evenly spaced relationship. The cooling coils are supplied with a refrigerant through inlet header 30 and inlet nipple 32. The heat exchanger is designed to cool air to a low temperature, as for example in the range of 40 F. A spray pipe 40 is mounted above the fin and cooling coil banks 24. It is journalled at its closed end in bearing 42 and mounted to swivel coupling 44 at its inlet end so as to extend transversely of fin plates 38. A leg 41 of angular bearing bracket 43 may be secured to end wall 16 of the casing 10 by bolts 45, as shown, or in any other suitable or desirable manner. Flange 46 of bearing bracket 43 extends perpendicularly to flange 41 and carries bearing housing 49 in which bearing 42 is mounted and journals the closed end of spray pipe 40. Swivel coupling 44 is mounted at end wall 18 and provides a pivotal connection between supply line or conduit and spray pipe 40. Thus, the supply line 50 may be fixedly mounted while permitting the spray pipe 40 to oscillate. The spray pipe 40 has depending branches 46 with nozzles 48 disposed at the ends thereof and forms a common conduit means for supplying antifreeze medium to the series of nozzles 48. The spray pipe 40 is supplied with a liquid antifreeze medium through supply line or conduit 50 and through swivel coupling 44. The nozzles 48 may be designed to pro- Another object of the invention is to provide such an improved heat exchanger in which the finned coils are uniformly sprayed or flooded with antifreeze medium, but utilizing a minimum volume of anitfreeze medium, thereby to avoid overflooding and partial blinding of the finned coils by such excess of viscous antifreeze medium.

Another object is to apply such viscous antifreeze medium with a minimum number of nozzles moved by a simple, inexpensive and reliable fluid motor which is driven by a part of the antifreeze medium.

Other objects and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary front elevation partly in section of the heat exchanger of the invention.

FIG. 2 is a fragmentary side elevation of the heat exchanger of'FIG. l, partly in section, taken on line 2-2 of FIG. 1 looking in the direction of the arrows.

FIG. 3 is a section taken on line 3-3 of FIG. 1.

FIG. 4 is a section taken on line 4-4 of FIG. 1.

FIG. 5 is a section taken on line 5-5 of FIG. 1 illustrating the spray oscillating mechanism.

FIG. 6 is a section taken on line 6-6 of FIG. 5.

FIG. 7 is a section taken on line 77 of FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION The heat exchanger is shown as having a casing 10 substantially rectangular in horizontal and vertical duce a flat stream discharge 52 extending transversely of the plates 38. The streams 52 meet or overlap slightly as shown in FIG. 1; the pipe 40 is oscillated to and fro in its bearing 42 and swivel coupling 44 so that an uninterrupted curtain of the viscous organic antifreeze medium is distributed back and forth along the banks of cooling coils and fins as best shown in FIG. 2. The nozzles 48 oscillate between dotted line position 48a and 4812 as shown in FIG. 2. With the fan-shaped streams 52 disposed transversely to the plates 38 it can be seen that they forcibly enter the spaces between the fin plates and forcibly wash the sides of the plates 38 as-well as the tubes 24. It should be noted, however, that in accordance with the broader aspects of the in-' vention the flat stream discharged by the nozzles may be disposed parallel to the plates rather than transversely as shown in the drawings to provide effective distribution of the antifreeze medium.

On end wall 18 there is secured a bracket 54 to which is attached a speed reducer gearbox 56 and turbine wheel 58 providing driving means for oscillating the spray pipe 40. The turbine wheel 58 is secured to the input shaft 61 of the gearbox for rotation therewith. A linkage transmission 60 is secured to the output shaft 62 of the gearbox 56. The bracket 54 includes splash cover 64 on the uppermost end thereof to which the gearbox is secured as, for example, by bolts 66. The linkage transmission 60 constitutes means for coupling the output of the gearbox 56 to the spray pipe 40. A driving link or crankshaft 68 is connected to the output shaft 62 of the gearbox 56. A connector link 70 is connected at one end through a lost motion connection 72 to the driving lever 68; at its other end the connector link is pivotally secured to a drive link or crank arm 74. The end of the pipe 40 adjacent the swivel connector 44 is threaded and the end of the crank arm 74 remote from the connector link 70 is secured to the pipe 40 by means of a pair of nuts 76 and 78 which clamp the end of the crank arm 74 therebetween, whereby the crank arm 74 is rotatable with pipe 40.

The turbine wheel 58 is fluid driven and is actuated tional area than the-cross sectional area of pipe 40, a

small portion of the antifreeze medium is conducted to the turbine wheel 58 at high velocity. Therotary motion of the turbine wheel 58 is transmitted and converted to oscillatory motion through transmission linkage 60 to pipe 40.

The casing below the tubular coil banks 24 houses a sump with an outlet nipple 82 to which the spent antifreeze medium from both the turbine wheel and the nozzles flows. The fluid may then be transmitted to a concentrator (not shown) for eliminating excess moisture absorbed during the de-icing function, if desired, and recirculated back through inlet nipple S0.

OPERATION OF THE DEVICE The operation of the heat exchanger and spray system should now be apparent. Cooling gases are conmodifications and other embodiments are possible within the scope of the invention.

What is claimed is: v

1. In a heat exchanger for cooling air having a casing, a bank of tubular cooling coils disposed within said casing, said cooling coils carrying a plurality of parallel fin plates in spaced relation thereon and means for passing low temperature cooling medium through said coils; a series of spray nozzles disposed on a side of said coil arranged to direct sprays of high viscosity anti-freeze medium to impinge against said cooling coil, adjacent nozzles being located to discharge a continuous spray from end to end across said bank of coils, common conduit means for supplying said liquid antifreeze medium to said series of nozzles to provide high velocity sprays and means for moving said spray nozzles relative to said bank of cooling coils to distribute said high viscosity antifreeze medium uniformly to said bank of cooling coils.

2. The combination according to claim 1 wherein each of said spray nozzles discharges a flat fan-shaped ducted through the return bend coils 24 through header 30 and inlet nipple 32 and out through header 34 and outlet nipple 36 through a compressor orother suitable cooling mechanism. To prevent condensation from freezing and forming ice on the cooling coils, therebylimiting their efficiency, the antifreeze medium is sprayed and uniformly distributed to the cooling coils 34 and fln plates 38 through pipe 40, branches 46 and nozzles 48. The antifreeze medium enters the pipe 40 through supply line 50 and'swivel coupling 44.'A portion of the antifreeze medium is diverted through conduit 80 and spout 81 to drive the turbine 58. The rotary motion of turbine 58 is transmitted through gearbox 56 and transmission linkage 60 to cause oscillation of the pipe 40 and attached nozzles 48. The oscillating spray completely and uniformly distributes the antifreeze medium to the cooling coil banks 24. The expended antifreeze medium from both the turbine 58 and the nozzles 48 gravitates to the sump at the lower end of the casing 10. The expended antifreeze medium may then be condensed to remove water vapors that have been absorbed in the de-icing process and then recirculated through supply line 50.

It sh mrldncTw'be apparent that a unique spray system for a heat exchanger has been provided for cooling a gas to a low temperature which utilizes a minimum number of spray nozzles and a minimum volume of necessarily viscous antifreeze medium in an economical manner. It distributes the antifreeze medium uniformly and completely to the finned cooling coil banks because of the novel oscillatory movement imparted to the nozzles. Although a certain specific embodiment of the invention has been shown and described for the purposes of illustration it will be apparent that various lapping to provide an uninterrupted spray from end to end across said bank of cooling coils.

3. The combination according to claim 1 wherein the liquid antifreeze medium is a viscous fluid at low temperatures.

4. The combination according to claim 2 wherein said bank of cooling coils comprise a plurality of aligned U-shaped tubes.

5. Heat exchange apparatus according to claim 4 wherein said means for moving said spray nozzles relative to said bank of cooling coils comprises drive means for oscillating said nozzles to and fro across the bank of cooling coils whereby said liquid antifreeze medium is uniformly applied to the plates and tubes.

6. The combination according to claim 5 wherein the drive means for moving said spray nozzles comprises a fluid operated turbine and linkage means for coupling said turbine to said spray nozzles for effecting oscillatory movement thereof.

7. The-combination according to claim 6 wherein said means for supplying said liquid antifreeze medium to said series of nozzles includes branch means for supplying fluid to drive said turbine. 8. In a heat exchanger for cooling air having a casing, tubular cooling coils arranged in a multi-layered rectangular array, said cooling coils carrying a plurality of parallel fin plates in spaced relation thereon and means for passing a low temperature refrigerant through said coils; a series of linearly spaced apart spray nozzles arranged to direct overlapping flat, fan-shapped streams of high viscosity anti-freeze medium to impinge against said array of cooling coils, common conduit means for supplying said high viscosity antifreeze medium to said series of nozzles to provide sprays of high velocity, through said common conduit means to said nozzles, fluid operated turbine means coupled to said series of spray nozzles for oscillating said spray nozzles to and fro about a common axis and ranch conduit means for supplying a portion of said antifreeze medium from said pump .to 'said turbine for driving said turbine.

9. A combination according to claim 8 wherein said flat fan-shaped streams of organic antifreeze medium extend transversely of said fin plates. 

1. In a heat exchanger for cooling air having a casing, a bank of tubular cooling coils disposed within said casing, said cooling coils carrying a plurality of parallel fin plates in spaced relation thereon and means for passing low tEmperature cooling medium through said coils; a series of spray nozzles disposed on a side of said coil arranged to direct sprays of high viscosity anti-freeze medium to impinge against said cooling coil, adjacent nozzles being located to discharge a continuous spray from end to end across said bank of coils, common conduit means for supplying said liquid antifreeze medium to said series of nozzles to provide high velocity sprays and means for moving said spray nozzles relative to said bank of cooling coils to distribute said high viscosity antifreeze medium uniformly to said bank of cooling coils.
 2. The combination according to claim 1 wherein each of said spray nozzles discharges a flat fan-shaped stream of liquid, the stream of adjacent nozzles overlapping to provide an uninterrupted spray from end to end across said bank of cooling coils.
 3. The combination according to claim 1 wherein the liquid antifreeze medium is a viscous fluid at low temperatures.
 4. The combination according to claim 2 wherein said bank of cooling coils comprise a plurality of aligned U-shaped tubes.
 5. Heat exchange apparatus according to claim 4 wherein said means for moving said spray nozzles relative to said bank of cooling coils comprises drive means for oscillating said nozzles to and fro across the bank of cooling coils whereby said liquid antifreeze medium is uniformly applied to the plates and tubes.
 6. The combination according to claim 5 wherein the drive means for moving said spray nozzles comprises a fluid operated turbine and linkage means for coupling said turbine to said spray nozzles for effecting oscillatory movement thereof.
 7. The combination according to claim 6 wherein said means for supplying said liquid antifreeze medium to said series of nozzles includes branch means for supplying fluid to drive said turbine.
 8. In a heat exchanger for cooling air having a casing, tubular cooling coils arranged in a multi-layered rectangular array, said cooling coils carrying a plurality of parallel fin plates in spaced relation thereon and means for passing a low temperature refrigerant through said coils; a series of linearly spaced apart spray nozzles arranged to direct overlapping flat, fan-shapped streams of high viscosity anti-freeze medium to impinge against said array of cooling coils, common conduit means for supplying said high viscosity antifreeze medium to said series of nozzles to provide sprays of high velocity, through said common conduit means to said nozzles, fluid operated turbine means coupled to said series of spray nozzles for oscillating said spray nozzles to and fro about a common axis and ranch conduit means for supplying a portion of said antifreeze medium from said pump to said turbine for driving said turbine.
 9. A combination according to claim 8 wherein said flat fan-shaped streams of organic antifreeze medium extend transversely of said fin plates. 